Tapetum Abnormal PCD Lead to Microspore Abortion in Anther of GMS Line Chinese Cabbage

Purpose To observe the cell morphology of tapetum and microspore during anther development of Chinese cabbage, in order to provide a basis for the study of anther abortion mechanism of nuclear sterility in Chinese cabbage.

Methods Near-isogenic line of GMS genes in Chinese cabbage, 10L03, was used as the experimental material. Paraffin section and TUNEL were applied to investigating cytological structures of fertile and sterile anther in this paper.

Results Anther abortion started at the meiosis stage, tapetal cell structure was abnormal. And microspores were aborted from tetrade stage on; after occurrence of sterility, tapetal cells swollen and formed enlargement and vacuolization, and was degraded in advance. Microspores deformed and wizened to die. Sterility was related to premature programmed cell death (PCD) of tapetal cells. Tapetal PCD process was out of control, which promoted tapetal explosive degradation in advance. Tapetum could not supply enough nutrition for the further development of microspores.

Conclusion Tetrads could not release mononuclear microspores in time. Microspores could not develop further, which was the direct cause to lead to microspores abortion.